Over Easy: The AN/ARC-5 Command Radio Set
Designed and built initially by Aircraft Radio Corporation of Boonton, NJ. Most all ARC-5 radio sets were made by Aircraft Radio Corporation as well as Stromberg-Carlson, Bendex and others. It is estimated that there were over a million units total manufactured for WWII aircraft use. The consisted of the ARC-5 receivers and transmitters and covered the frequencies of 190 KHZ to 550 KHZ, 530 KHZ-15. MHZ for radio navigation. And 1.5-3.0 MHZ, 3.0-6.0MHZ and 6.0-9.1 MHZ for communication – mostly aircraft to aircraft. All the Navy and Army Air Corp aircraft had them installed. Especially the Flying Fortresses – B17, B29 etc. But even the small er fighters had them installed. They were THE radio for aircraft communication during WWII.
They were single band units that were small and light weight. Almost completely aluminium except for certain precision parts. Easy to tune and operate they could also be operated remotely. The receiver had 2 RF amplification stages and 2 IF amplification and could receive both AM and CW [ Continuous Wave Morse Code]. The transmitter could send both AM voice and was as CW mores code. On a good day and all tuned up the transmitter could put out up 50 Watts of CW signal. Not bad for a rig not much bigger than a lunch box.
And the receiver was fairly sensitive with smooth accurate tuning and both could be locked down so the radio man or pilot could not change frequency when set by the technicians on the ground. Both units used the tubes of the day. Metal octal base tubes which were fairly large. The transmitter using 1625 tubes designed by RCA specifically for the purpose.
They were still in production and use into the early 1950s.
Aircraft Radio Corporation was eventually bought by Cessna Aircraft specially to make radios and other avionics for them and continued well into the 1970s.
But the little ARC-5 did not stop there. After the war was over they began to show up on the surplus electronic market and Ham Radio operators bought them up by the truck loads. There began to be articles in the various radio magazines for conversion to Ham Radio frequency bans. Books published both here and in Europe and Great Briton. How to use them as add ons and accessories to other radio equipment. How to make the transmitter crystal controlled so they would be legal for a Novice Class Ham Radio operator to use.
One of the favorite uses for the radio navigation LF receivers was as a Q5er
The low frequeney BC 453 had sharp 85kHz IF’s and was used to sharpen up many a receiver by extracting the 455 kHz signal from the HF receiver and inserting it into the Q5er’s front end.
Giving that old pre WWII commercial receiver a real boost. And the best part was that they were cheap. You could if you looked around hard enough pick up a complete AR-5 set for as little as 5 bucks. Still a lot in the 1950s for a young Ham Radio operator but much less than a new or even used commercial unit.
But times changed. In the mid 1950s the military converted from AM voice to Single Sideband Voice or SSB for short. And Hams followed suit. The big Boatanchor separate receivers and transmitters went out of favor along with their accessories. Small transceivers were what was wanted and the ARC-5 fell out of favor. Miniature tubes and then transistors became the rage. Small table top all in one units.
You can still find – even new in the box – ARC-5s on ebay and even swap feasts. There are those who like to collect them and restore them to their original condition. And they still have something going for them. The receiver and transmitter tuning used a worm gear coupling and drive mechanism which gives them a nice smooth and precise tuning you could only find in very high end gear of the time. And they are very easy to work on as all the units use the same or similar parts through out.
Here is a demo of one of these little guys.
Not bad for a 70+ year old set, eh. So what’s on your mind Firedogs ? Anything goes here.